1. Field of the Invention
The present invention relates to a recording medium.
2. Description of the Related Art
Japanese Patent Laid-Open Nos. 7-76162 and 2010-30291 disclose a recording medium that includes a porous layer and an outermost layer on a substrate so as to improve ink absorbency and scratch resistance. The porous layer contains alumina, alumina hydrate, dry silica, wet silica, or the like. The outermost layer contains particles of silica gel, colloidal silica, or the like. Japanese Patent Laid-Open No. 7-76162 discloses that a recording medium that includes a porous layer and an outermost layer on a substrate has improved ink absorbency and scratch resistance. The outermost layer contains a silica gel having a size of 10 nm or more and 90 nm or less. Japanese Patent Laid-Open No. 2010-30291 discloses that a recording medium that includes a porous layer and an outermost layer on a substrate has improved ink absorbency. The outermost layer contains spherical colloidal silica particles having a size of 105 nm or more and 200 nm or less.
However, the present inventors found that the recording media according to Japanese Patent Laid-Open No. 7-76162 and No. 2010-30291 sometimes have interference fringes, a phenomenon in which the surface glistens in all the colors of the rainbow. There is also room for improvement in ink absorbency and scratch resistance of the recording medium described in Japanese Patent Laid-Open No. 7-76162. There is also room for improvement in scratch resistance of the recording medium described in Japanese Patent Laid-Open No. 2010-30291, although the recording medium has high ink absorbency.